The above noted vent has a screen therein, normally placed at a horizontal plane. The purpose of the screen is to prevent. birds or other animals, such as vermins, from entering the duct and to proceed into the house. However, it has been found that this screen has the disadvantage of collecting lint coming from below because this lint is being expelled by the clothes dryer in its air stream passing therethrough. consequently, the efficiency of the dryer is diminished because the flow of the air stream is impeded as it tries to pass through the screen. This build-up of lint on the screen can become so bad until the dryer can not function at all anymore because the hot and moist air remains in the dryer. This results in a great expenditure of energy because the dryer may run at double the time it was designed for if not more.
During a database search of patents, no references were found that would address the above noted problem.
U.S. Pat. No. 5,147,244 is concerned with a roof vent located at the ridge of the roof including a control apparatus therefor, but it is designed to vent the whole of a building and not a single appliance.
U.S. Pat. No. 4,546,919 is concerned with a ventilator actuator to control the internal temperature of a building.